Tuning strong metal-support interactions to boost activity and stability of aluminium nitride supported nickel catalysts for dry reforming of methane

Abstract

Strong metal-support interactions (SMSI) occurring on oxygen-free supports have attracted significant attention in the catalysis field. The oxide layers often cover a part of the active metal sites, especially at elevated temperatures. Here, we report on tunable SMSIs between nickel nanoparticles (NPs) and oxygen-free hexagonal aluminum nitride (h-AlN) via the hydrothermal-assisted degradation method. The key to this interaction is constructing a thin Al2O3 layer on the AlN surface from the Al(OH)3 intermediate, which combines with NiOx species to redisperse Ni NPs in the reductive atmosphere. Besides, the strong interactions (Al2O3-Ni-AlN) build a dynamic balance between Ni0 and Ni2+ to prevent Ni oxidation toward the supporting interior. Al-O/Al-OH sites work synergistically with coated Ni sites to promote the dry reforming of methane (DRM) reaction. Thus, Ni/h-AlN@40–3 h catalyst with a thin Al2O3 layer shows high conversion and long-term stability. This strategy may offer a promising and controllable approach for the industrial application of DRM catalysts.